Aim: We aim to investigate erythropoietin (EPO) response to anemia and its association with autonomic neuropathy in type 2 diabetic patients without advanced renal failure.
Methods: A cross-sectional study was conducted on 211 type 2 diabetes mellitus patients without advanced renal failure [estimated glomerular filtration rate (eGFR) >40 ml/min/1.73 m(2)]. The response of EPO to anemia of type 2 diabetic patients without advanced renal failure was compared with those of nondiabetic control subjects. Autonomic nerve function was assessed using three cardiovascular tests (deep breathing, the Valsalva maneuver, and lying-to-standing). The results of each test were scored as 0 if normal, 1 if borderline, and 2 if abnormal. Autonomic neuropathy was diagnosed when a total score of the tests was 2 or more.
Results: Fifty-eight patients were anemic; compared with nonanemic patients, they had a longer duration of diabetes (16.69+/-10.11 vs. 10.67+/-8.41 years, P<.001), lower eGFR (66.43+/-16.30 vs. 81.74+/-19.49 ml/min/1.73 m(2), P<.001), and higher cardiovascular autonomic neuropathy score (3.17+/-1.95 vs. 1.79+/-1.72, P<.001). Serum EPO level was weakly correlated with hemoglobin (Hb) level (r=-.085, P<.001). However, the slopes of regression lines between EPO and Hb levels differed significantly between type 2 diabetic patients and nondiabetic control subjects (-0.0085 vs. -0.255, P=.008). Multiple linear regression analysis revealed that cardiovascular autonomic neuropathy score was independently related to Hb (P<.001) or EPO level (P=.052).
Conclusions: Autonomic neuropathy is associated with a blunted EPO response to anemia in type 2 diabetic patients without advanced renal failure.